sledfvr
Pro
I've been thinking of getting rid of my old bender rear mount gt2860 kit. I found an older cpr kit for a pretty good price. I am wondering about the efficiency of the older style cpr intercooler? It looks pretty small. My bender kit has a tunnel cooler and a decent sized ic. I ride mountains only with back to back pulls and don't want to heat soak too bad. If I went with the cpr kit It would definitely spool faster and I would get a mesh hood for more airflow. I would probably get a different header for it too. I'm curious how many pounds of boost the old cpr ic's are good for?
Rx1M5
VIP Member
I run one and it's just OK but if you are already running 380 hp like your sig says I don't think the CPR intercooler is your best choice. The Bender intercooler is probably just as good or better. My buddy runs a Bender so I've seen the IC quite a bit. I've heat sinked my CPR to the point where I could barely touch it. One thing I don't like about the CPR cooler is it weighs a ton. I'm actually removing my CPR system and going a different route but for now I will be keeping the IC. If your interested I'll have a Powderlites header, front mount fuel tank and divorced double down pipe for sale soon.
Rx1M5
Rx1M5
Ted Jannetty
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sledfvr said:
Efficiency of the intercooler, Count the 90 degree turns the air has to make 4 comes to mind.
Not only that but all the air is loaded in one side of the carburator tank.
Someone who will remain nameless recently had an air filter fall off during a grass race and injested a bunch of dirt so engine disassembly was necessary the cylinder closest to the air inlet on the carb tank was loaded with dirt where the other three only had a small amount of dirt so this confirms our suspicions about which carb gets the most air.
This intercooler design is the one that makes the most sense.
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Rx1M5
VIP Member
After this came up I started getting curious about my own intercooler and found the following on a car site.
Sure. A bar and plate IC will have a lower pressure drop than a tube fin. However, because the tubes have square leading and trailing edges, they tend to force cooling air around the core, rather than between the rows.
A tube fin of the same size and design will have a higher pressure drop because it has less volume inside the rows for charge air. However, since the leading and trailing edges of the tubes are rounded, they "channel" more air in between the rows.
Here's where tube fin comes out on top- make the core or the rows slightly larger than the bar and plate to make up the pressure drop difference and you'll have an IC that will flow as well as a bar/ plate, and will cool more efficiently because the rows are seeing more cooling air between them.
If this doesn't make sense, I can draw a picture to show what I mean.
I also went to Garrett's web site and started reading their Turbotech on intercoolers and found the end tank deisgn on the CPR cooler is rated as a good one by Garrett so then I started thinking maybe the CPR intercooler being a Tube & Fin design is better than I thought.
Rx1M5
Sure. A bar and plate IC will have a lower pressure drop than a tube fin. However, because the tubes have square leading and trailing edges, they tend to force cooling air around the core, rather than between the rows.
A tube fin of the same size and design will have a higher pressure drop because it has less volume inside the rows for charge air. However, since the leading and trailing edges of the tubes are rounded, they "channel" more air in between the rows.
Here's where tube fin comes out on top- make the core or the rows slightly larger than the bar and plate to make up the pressure drop difference and you'll have an IC that will flow as well as a bar/ plate, and will cool more efficiently because the rows are seeing more cooling air between them.
If this doesn't make sense, I can draw a picture to show what I mean.
I also went to Garrett's web site and started reading their Turbotech on intercoolers and found the end tank deisgn on the CPR cooler is rated as a good one by Garrett so then I started thinking maybe the CPR intercooler being a Tube & Fin design is better than I thought.
Rx1M5
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sledfvr
Pro
Thanks for all the info. My bender i/c looks almost identical to the one Ted shows...only the inlet tube is on the other side. My i/c has never even been hot to the touch with my bender kit. I think the snow cooler does a lot of good. I don't know if any air i/c is very efficient with the poor angle they are on and all the battery crap behind them restricting airflow. Then factor in the sled being straight up and down all day climbing hills and there is probably little to no air flowing through the i/c.
I am not sure which direction I'm going to go here. I'd like quicker spool up, but I not sure I want to deal with all of the heat up front or getting rid of my snow cooler. I really like the design of Impulse i/c and header setup, but it is spendy. Thanks for all the info.
I am not sure which direction I'm going to go here. I'd like quicker spool up, but I not sure I want to deal with all of the heat up front or getting rid of my snow cooler. I really like the design of Impulse i/c and header setup, but it is spendy. Thanks for all the info.
rxrider
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What Ted says, that's the only way to eliminate sharp corners and 90 deg changes in the air flow. The one in the pic is the most efficient with the best cooling, most even filling of the carbs and the least pressure drop over the IC.
